The present invention relates to memory arrays, and more particularly to multi-level memory arrays with memory cells that employ bipolar storage elements and methods of forming the same.
Non-volatile memories formed from reversible resistivity-switching materials are known. For example, U.S. patent application Ser. No. 11/125,939, filed May 9, 2005 and titled “REWRITEABLE MEMORY CELL COMPRISING A DIODE AND A RESISTANCE-SWITCHING MATERIAL” (hereinafter “the '939 application”), which is hereby incorporated by reference herein in its entirety, describes a rewriteable non-volatile memory cell that includes a diode coupled in series with a reversible resistivity-switching material such as a metal oxide or metal nitride.
However, fabricating memory devices from rewriteable resistivity-switching materials is difficult; and improved methods of forming memory devices that employ resistivity-switching materials are desirable.